Internal combustion engine



Nov. 123, 1937. A. K. ZIMMERMAN INTERNAL COMBUSTION ENGINE Filed May 1, 1934 Inventor 5 Sheets-Sheet 1 jzzz'innzerlna 22/ M flilorney I Nov. 23, 1937. A. K. ZIMMERMAN 2,100,064

r INTERNAL COMBUSTION ENGINE Filed May 1, 1934 5 Sheets-Sheet 2 Invenlor ilizz'innzer'nz aiz f1 ttorney Nov. 23, 1937. A. K. ZIMMERMAN 2,100,064

INTERNAL COMBUSTION ENGINE Filed May 1, 1 934 5 Sheets-Sheet 3 Inventor f1 llomey Nnv. 23, 1937. zlMMERMAN 2,100,064

INTERNAL COMBUSTION ENGINE Filed May 1, 1934 5 Sheets-Sheet 4 O 0 9| IO 0 o Q 0 o o 0 O 0 w J j 0 v 7 O2 a q Invenlor Nov. 23, 1937.

A. K. ZIMMERMAN INTERNAL COMBUSTION ENGINE Filed May 1, 1934 5 Sheets-Sheet 5 Inventor v jfza'mnzerfizaiz Patented Nov. 23, 1937 UNITED STATES PATENT orries INTERNAL COMBUSTION ENGINE Alvin K. Zimmerman, Akron, Ohio Application May 1, 1934, Serial No. 723,373

6 Claims.

.inders and then fed to the combustion chamber or working cylinders, and an important object of my invention is to provide an internal combustion engine of the type indicated which is highly simplified and efiicient. I

It is also an important object of my invention to provide in an internal combustion engine of the character indicated a two-cycle charge compressing unit and a four-cycle working unit, thereby greatly increasing the compression of the charge before it is fed to the working cylinders and more favorably vaporizing the same.

Other objects and advantages of my invention will be apparent from a reading of the following description in connection with the drawings, wherein for purposes of illustration I have shown a preferred embodiment of my invention.

In the drawings:-

Figure 1 is an elevational view of the righthand side of the embodiment.

Figure 2 is a transversevertical sectional view taken through Figure 1 approximately on the line 2- 2 and looking rearwardly in the direction of the arrows.

Figure 3 is another transverse vertical sectional view taken through Figure 1 approximately on the line 3+3.

Figure 4 is a top plan view of Figure. 1.

- Figure 5 is a transverse sectional view through one of the wrist pins, showing the manner of connecting the upper end of the connecting rod thereto. p g V Figure 6 is a transverse vertical sectional view through a portion of the valve mechanism.

- Figure 7 is a horizontal sectional'view through one of. the pistons.

Figure 8 is a diagrammatic representation of and showing the relationship of the two-cycle and four-cycle cam shafts.

-Referring in detail to the drawings, the numeral 5 generally designates the oil pan which depends from the crankcase 6 from which rises the cylinder block 1, the topof which is closed by the cylinder head 8. The numerals 9, ll] represent the valve chamber covers-of the working part of the engine and of the charge compressing part, respectively.

1 The crank shaft projects forwardly and rearwardlyfrom the bearing structures I I, l 2, respectively, formed on opposite sides of the point of separation of the crankcase and the oil pan, and

on its rear end has the flywheel l3 and on its I front end the fan belt driving pulley M which has trained thereover the fan belt 55 which is also 7 trained over the fan pulley it on the fan shaft H which is also the impeller shaft for the Water pump !8 which is mounted as indicated on the front end of the cylinder head it and combined with the cooling water outlet 19. The fan is fixed on the front end of the fan shaft ll.

The exhaust pipe 2! has the vertical portion and another branch leading from the same point thereof and indicated by the'numeral 26 is. a portion of the exhaust manifold 21 of the working portion of the engine. The intake manifold 28 which feeds only the compressing part of the engine has the depending portion 29 to which is connected a suitable carburetor (not shown).

The oil pan 5 has supported therein above the bottom the tray 30 which has the depressions 3! under the throws of the crankshaft so as to form sub-reservoirs in which the lower end of the connecting rods 32 work and use their cups or vanes 33 to throw and splash the oil in the crankcase to the bearings.

Webs 3 L 01? double fan-shape are arranged across the lower portion of the crankcase 6 to provide the upper bearing for the crank shaft, the lower part of these bearings being constituted by removable caps 35 which are bolted to the corresponding webs fi l as indicated at 38.

At the right hand side of the crankcase at the top thereof are the inwardly projecting brackets 37 supporting the cam shafts 38, 43. The cam shaft 38 operates the valves of the working part of the engine. The front end of the cam shaft 38, has fixed thereon the pinion 42' which is in mesh with the idler pinion i i which is in turn in mesh with the gear it on the front end portion of the crankshaft id. The cam shaft 43 operates the valves in the compressing part of the engine. It is arranged that the cam shaft 43 will be 0perated at the same rate of rotation as the crankshaft, while the cam shaft 38 rotates only once for every two revolutions of the crankshaft 44. The gears or pinions 40, it and 42 may be of any suitable material such as the composition mate rial now generally. used for gears of this type, so that the gears will be silent and long-wearing. The idler gears ii and are suitably supported within the crankcase as indicated. The crankshaft gear 49 is only half the size of crankshaft gear 40.

The working portion of the engine, particularly shown in Figure 3, comprises within the motor block 7 and head 8 the water jacket 45, the spark bearing portion l5 and a lower bearing portion 5| which are bolted as indicated at 52 to confine a V removable bearing 53.

The upper end ofeach engine is connectedto the Wrist pin 53 of each of the pistons in the manner, indicated in Figure 5, The upper end of the connecting rod is circular asrindicated at' 54 and is split at one side as indicated at 55 to provide the upperand lower furcations 56, 51 which are arranged to be clamped together by a bolt 58 which traverses them. A notch 59 in the adjacent side of the wrist pin 53 is engaged by the bolt 58 so as to lock the wrist pin against turning relative to theconnecting rod, and to lock the wrist pin against moving longitudinally or axially relative to the connecting rod. As shown in Figure 7 a simplified form of piston is used which has the wrist pin supporting members 58 and 6E whose aligned bores have bushings 62, 63 of removable type which arefl'anged as indicated at 64, 55 and their inward ends provide shoulders which act as bearings presented to'the opposite sides of the portion 54 of the connecting rod;

The valves 66 leading to the pump cylinders are of the mushroom type and include the stem 61 Iwhich works through a solid guide portion 68 in the upper part of the motor block, the lower part of' the stem working in the valve chamber 69 where a helical spring is circurnposed thereon and works between the top of the chamber and a cupshaped retainer H which is held in place by a washer 12 locked by a'pin '13 and presenting its lowerend to the tappet '74 which worksthrough the removable bushing '55 seated in an appropriate 'opening in the lower wall oi the valve chamber and extending into the crankcase, as shown in Figure 6, to be operated by the cam shaft 538. It

is to be noted that the cam shafts38 and #23 are axially aligned and spaced, and as already pointed outthese cam shaftsare in a 2 to 1' speed ratio of rotation. I? In the embodiment shown the working portion of the engine includes four cylinders E8 in line, While the compressing portion comprises two larger cylinders l? in line and aligned with the working cylinders. The exhaust 18.01 the compressing part of the motor discharges into a manifold 19; which is the intake manifold for the working part of the engine.

The compressing cylinders with their pistons 80, connecting rods'8l, wristpins 82, connecting rod 'bearings'83, and watenjackets .84 are generally similar instructure and arrangement to the corresponding parts of the working part of V the engine. 7

Instead of having exhaust valves'in the upper. part of the motor block as in the ordinary L-head type of motor as obtains in the case of the working parts of the engine, the exhaust valves 850i the compressing part of theengine seat in openings 86 in the central portion of the head 8 and V have their stems 81 rising above the heads and threadedras indicated at 88 and slotted as indicated' at 89; The smooth part of the stem 8'! works through the web fill of, the hollow hous 7 ing 9|.

. An 'extensi justably connected to the upper end of the stem 8; W,9 i 5 e. Herman. 0f he ousineabqveilie connecting rod in the back, the firing order is as follows:-

( 1 or a) (5) (o "F s o 7E :0 s E o F 's' s 0 S .F E' o o s c E s F s 0 F. s c n; -.o s

on 92 of the'stem 8'1 which is ad web or partition 90 and encircling this extension is the valve spring 93 which works against the compressing cylinders "has a housing 9| with the valve mechanism described, and a discharge conduit 95 leading from the lower'part thereof and joining the branch 23 of the exhaust manifoldslB and 19. The branch-25 of the exhaust pipefll lea'ds" to a' smaller conical housing 96 1 which is supported at one side of; the working part of the engine as shown in Figure 3. Within the housing 95 is a valve 9'l working against the seat 98 in the lower part of the housing and having'the extension 99 working in the upper part of the housing and pressed to seat by the spring I00 working against the'retainer Illl, and the housing is mounted on the'upper side of the intake manifold'lS; The housing 95 and its attendant mechanism operates as a safety valve in case of back fire, t 'by-pass the back fire 'into the'exhaust pipe 21, the increased back-pressureconse quent upon a back fire beingad'equate to open the valve 9} to permit the. back fire to pass to the exhaust pipezl; This arrangement prevents, back firinginto the compressing Dart of the engine, which is necessary'f or safety and proper operation of; the compressing, part of the engine.

'Givingthe cylinders numerals from front to N0te:-F.='Firipg.' 7 S=Suctioii stroke.

0 C ompressing stroke. E=Exhaust stroke.

It will also be noted that compression cylinder 5 supplies the charge for working cylinders 1 and 2.wh1le compressing cylinder 6 supplies theoharg .forworking de e ld 1r sthe pe agreatest eificiency it is found that long stroke pis-" tons of relatively small diameter inthe' working part ofthe' engine areadvisable to take careof the relatively enormous expansion of the ;highly' compressed charge therein, which is further com Pressed ih m e Qf hewor n s on. It will be observed thatthe course of the charge from the point of itsintroduction into the compression unit to the combustion chambers is ofisuch duration that an unusual opportunity ispresented to vaporize andtc be completely vaporizedwhen finally delivered to the working cylinders; 'll'ie camshaft of the compressionpart of the engine makes one revolution to each revolution of the crankshaft, while the cam shaft for operating t e h us n ntake valves o e w k n pa oif thefengine rotates at half the rate of rotation of the other camshaft. -The valve mechanisms 'Each of the compressing cylinders has an intake and an exhaust valve similar in structure to the valves in the working part of the engine, and the compression part valves are operated by the cam shaft 38, the working part valves being operated by the cam shaft 43, the intake valves receiving the gas from the carburetor through the intake manifold 28 and the exhaust valves discharging through the workingpart intake manifold I9.

It will be obvious that in case of a back fire or excess pressure in I8 and 19 the pressure therein will open the valve in the housing 96 and will close also the valves 85 in the housings 9 I, thereby creating a situation in which the only path of escape of the back fire is through 25 and into the exhaust pipe 2 I.

A suitable type of relief valves I02 is provided in the head to release the pressure within the compression cylinders I! when starting the engine. Otherwise, the relatively'weak starting impulses of the engine would not be equal to operatchange or changes may be made in material and structure and arrangement of parts, within the spirit of the invention and the scope of the subjoined claims. I

What is claimed is:--

1. In an internal combustion engine of the character described having a cylinder block containing working cylinders and compression cylinders, each of the working cylinders having an exhaust and an intake valve and each of the compression cylinders having an exhaust valve and an intake valve, a carbureted gas supply to the compression cylinders, an intake manifold for said working cylinders, an exhaust conduit to which said working cylinders discharge, and a safety valve on said intake manifold arranged to discharge to said exhaust conduit.

2. In an internal combustion engine of the character described having a cylinder block containing working cylinders and compression cylinders, a crankshaft supported in connection with the cylinder block, pistons in the working cylinders and in the compression cylinders operatively connected to said crankshaft, each of the working cylinders having an exhaust and an intake valve and each of the compression cylinders having an exhaust valve and an intake valve, a first cam shaft for operating the valves of the working cylinders, and a second cam shaft for operating the valves of the compression cylinders; a carbureted gas supply to the compression cylinders, an intake manifold for said working cylinders, and means for firing the charge in the working cylinders, said intake manifold having a safety exhaust valve, said engine having an exhaust conduit to which said safety valve is connected; and a safety valve for each of the compression cylinders discharging to said exhaust pipe, and arranged to .be closed by excessive pressure present in said exhaust pipe. 1

3. In an internal combustion engine of the character described having a cylinder block containing working cylinders and compression cylinon each compression cylinder arranged to dis-' charge to said exhaust conduit.

4. In an internal combustion engine of the type described comprising a working cylinder including an intake and an exhaust valve, a compressing cylinder including an intake valve and a first exhaust valve and a second exhaust valve, a manifold connecting the compressing cylinder first exhaust valve with the working cylinder intake valve, a second manifold leading from the said second exhaust valve and the exhaust valve of the working cylinder, a safety valve communicating with said first manifold, a conduit leading from said second manifold to said safety valve, a second conduit leading from said second manifold and communicating with said first exhaust valve, said safety valve and said first exhaust valve being resiliently seated and arranged to be closed by excessive pressure present in said second manifold.

5. In an internal combustion engine comprising working cylinders and compressing cylinders, each of said cylinders having an intake valve and an exhaust valve, a fuel manifold connecting all of the compressing cylinders with some of the working cylinders", an exhaust manifold leading from said working cylinders, first safety valve means in communication with said compressing cylinders and said exhaust manifold, second safety valve means communicating with said fuel manifold and with said exhaust manifold, the first and second safety valve means being normally lresiliently closed and arranged to open upon development of excess pressures in said working cylinders and in said fuel manifold, respectively, and arranged to be opened by excessive back pressure in said exhaust manifold.

6. In an internal combustion engine comprising working cylinders and compressing cylinders, each of said cylinders having an intake valve and an exhaust valve, a fuel manifold connecting all of the compressing cylinders with some of the working cylinders, an exhaust manifold leading from said working cylinders, first safety valve means in communication with said compressing cylinders and said exhaust manifold, second safety valve means communicating with said fuel manifold and with said exhaust manifold, the first and second safety valve means being normally resiliently closed and arranged to open upon development of excess pressures in said working cylinders and in said fuel manifold, respectively, and arranged to be'opened by excessive back pressure in said exhaust manifold, said first and second safety valves each comprising a casing having one end surrounding a valve opening in the corresponding cylinder or fuel manifold, a web across the casing, a valve stem slidable therethrough and having a head cooperating with the corresponding valve opening, a spring on each stem and engaged between one end of the casing and a portion of said stem, and a side port in the casing axially inwardly of said web and axially outward of said valve head, said port being connected with said exhaust mani- 

